Until now, the deal-making by top-flight clubs in England has been a steady flow of unremarkable transfers, with Leicester City's £15m move for Genk midfielder Wilfred Ndidi the biggest fee prior to Schneiderlin's imminent switch from Old Trafford to Goodison Park.

Middlesbrough have invested £6m in Aston Villa forward Rudy Gestede, Hull have spent £4.5m to sign AZ Alkmaar midfielder Markus Henriksen permanently -- he now faces a spell on the sidelines with a shoulder injury -- and Everton have looked to the long term by paying £11m for Charlton Athletic teenager Ademola Lookman.

But while the Premier League is likely to exceed last January's overall transfer outlay of £175m, the big deals had been thin on the ground before Everton's breakthrough in negotiations for Schneiderlin.

Ronald Koeman has convinced his board to fend off rival interest in the France international from West Bromwich Albion, and the former Southampton player could now make his Everton debut against Manchester City at Goodison this weekend.

But with Everton now leading the way, expect an escalation in the transfer battle between now and Jan. 31, when the window will close at 11 p.m. GMT.

The Schneiderlin deal is likely to be the key which unlocks the window and triggers a domino effect of transfers.

United now have £22m with which to reinvest in Jose Mourinho's squad and, while they are prepared to wait until the summer to do their business, a move for Monaco midfielder Tiemoue Bakayoko cannot be ruled out this month with United aware of Chelsea's rival interest in the 22-year-old.

Chelsea, with £60m in their transfer kitty following the sale of Oscar to Shanghai SIPG, have so far sat tight on their windfall, but having noted Schneiderlin's departure and the hole it has left in Mourinho's United squad, they may also now jump into action to snatch Bakayoko.

But further down the table, other clubs have been affected by Schneiderlin's move.

West Brom must now shift their sights to other targets having missed out on Schneiderlin, forcing manager Tony Pulis to consider whether to firm up his interest on Hull City's Robert Snodgrass and Leicester's Jeffrey Schlupp.

West Ham are also keen to sign Scotland midfielder Snodgrass, having already had a £3m bid rejected by Hull, but manager Slaven Bilic will be aware of the ripple effect of Schneiderlin's transfer and its impact on West Brom, so his interest in Snodgrass may also be given a jolt.

West Ham have already sent Simone Zaza back to Juventus following his unsuccessful loan spell, but Zaza's name has now been linked with Hull, so the Italian could find his way back to the Premier League quickly.

Sam Allardyce is one of several managers at the wrong end of the Premier League looking to recruit this month.

Both Sam Allardyce at Palace and Paul Clement at Swansea have been told that they will have money to spend this month to bolster the struggling squads they inherited recently.

Clement wants to bring PSV Eindhoven's Luciano Narsingh to the Liberty Stadium, while Allardyce could make as many as four new signings at Selhurst Park.

Frank Lampard, a free agent following the end of his contract with New York City FC, is one player who has been linked with a move to Palace, and Allardyce has shown in the past his readiness to make bold signings in the dying days of the window.

But one certainty is that, after a low-key start to the transfer window, Schneiderlin's move to Everton will set in motion many more deals between now and deadline day.

Mark Ogden is a senior football writer for ESPN FC. Follow him @MarkOgden_